78 johnson 115 will not start

gasrodjr

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Jun 25, 2013
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I got a 1978 Johnson 115 on a Mako 17 foot center console for free. It had been sitting for 5+ years in some ones back yard. I removed and rebuilt the carburetors. It has spark and will start if I put fuel into the cylinders. The ball pumps up hard on the fuel line and the spark plugs look wet after cranking it for a while. It spins over just fine and has good compression.
I don't know that much about outboards. i am a master automotive technician so I understand the basics of how engines work. Any suggestions will be great. Thank you.
 

alldodge

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It had been sitting for 5+ years in some ones back yard. .....
It has spark and will start if I put fuel into the cylinders. The ball pumps up hard on the fuel line and the spark plugs look wet after cranking it for a while.

I would run the motor off a gas can
Best guess now is the gas in the tank is bad. This is why it starts if gas is put in cylinders but not from the tank.
 

gasrodjr

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Jun 25, 2013
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I would run the motor off a gas can
Best guess now is the gas in the tank is bad. This is why it starts if gas is put in cylinders but not from the tank.
been trying to start it from a seperate gas can to eliminate the fuel problem. even tried to bypass the fuel pump and put the fuel straight to the carburetors and the ball pumped up hard but not even trying to start. is there a chance that the engine is full of bad fuel and it needs to spin over more with the choke on to get new fuel into the engine?
 

racerone

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Dec 28, 2013
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Stop.----Is the choke solenoid working and properly adjusted ?------The motor needs to spin fast with the starter in order for ignition system to work.-------So load test the battery.-----Take starter apart for inspection and ohm check on armature.----Inspect battery cables.
 

F_R

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I second the cranking RPM suggestion. Will it produce a 7/16" open-air spark while cranking with the plugs in?
 
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